High Technologys Cracking Tutorial

*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*
:* *:
*: High Technology's :*
:* Cracking Tutorial *:
*: :*
:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:*:
Written by:
High Technology & Sherlock Apple!
=-----------------------------------------------------------------------------=
Written for: Sherwood Forest ][ and Sherwood Forest ///
_______
/ \
< Preface >
\_______/
This series is aimed to help you de-protect certain programs to make back-up
copies of the programs hereafter, and only for that purpose. The authors take
no responsibility for an(y) illegal cop(y)(ies) made by the end user of this
information, nor any damage to programs, hardware, or any other physical damage
done by the use of the information hereafter.
The authors urge you to attempt to make nibble copies of the program before
attempting any modification to the program. The techniques described in this
series may not work on all versions of the program. In most cases there are
many other ways to de-protect the program (such as nibble counts) and if any of
you know of a better way please let us know.
More advanced crackers or programmers who know machine language pretty well
might want to skip the text and just read the => prompts. The -> prompt
indicates a place in the instructions where you may not need to go any further.
=-----------------------------------------------------------------------------=
This weeks topic: Xerox educational games
=------------------------------------------------------------------------------
Xerox is known for their excelence in education games such as the Stickybear
series, Chivalry, Fat City, Pic Builder, and others. The protection on these
games is fairly standard, a single nibble count. To modify the nibble count so
it does not function, we need a sector editor. Inspector is the most popular,
although the sector editors in Nibbles Away ][ and Copy ][+ both are fine. Of
course, we suggest you make a back-up of the program before modifing any data.
=> Read Track 2, Sector 6
=> Change byte $00 from $A9 to $60
=> Write Track 2, Sector 6 back to disk.
Notes: You just disabled the nibble count. The start of the routine was at, of
course, Track 2, Sector 6. The routine was in machine, so $A9 (the first byte
of the routine) stood for LDA (LoaD Accumulator). By replacing it with $60
(which stands for RTS, or ReTurn from Subroutine) we returned to the main
program without doing the nibble count. This will not work for ALL of the Xerox
software, such as Stickybear Bop and Pic Builder, but will work for almost all
of it.
=-----------------------------------------------------------------------------=
_________________
| |
| Happy Cracking! |
| High Technology |
| The Apple Mafia |
|_________________|
- End of File -